Thermocouple Vs Pt100

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Fantasy Brewer
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I must win some sort of award for the best scrounge of the day - possibly even the month.
I have just obtained, gratis, a Gefran 500 temperature controller (may or may not be working, and two Fuji PXZ4 temperature controllers (new in box).

I am a *******, and I know it for having to mention this you all....

What I didn't obtain, are probes suitable for these units, so i will have to spend some dollars to get the gear that I need. The question is, what sort of probes should I get? I am overwhelmed with options according to the manufacturers with an array of thermocouples and PT100 3 or 2 wire sensors being compatible.

What should I be looking for for? and any idea what they will cost me?

(who goes home happy this weekend) :D
When you know what sort you need for the controller
PM me with the details , never know you may still be on a winner ;)
Those temperature controls are brilliant for controlling a brew fridge. I'd get yourself a pt100 ( or RTD as they're often called) as they are far more accurate. I've got one one these thing attached to my brew fridge which I acquired very cheaply and they are fantastic. I'd probably check first if that fuji model supports pt100, because it may just be suited to thermocouple only. Pm me if you'd like any help, as i've installed a few of these things over the years, being a electrician and all.
Best advise is to find the local agent and get an appropriate probe for that model from them. If you have to buy a locally made replacement it will be around $40 to $50 for an RTD and a little less for a thermistor or thermocouple type. Incidentally, the thermistor types are real trick to replicate. RS Compnents have a huge range of thermistors but unless you know the exact resistant gradient its impossible to select the correct one.

We are just commissioning a (second hand) 800ltr micro which has 10 probes - all thermistor types. If we were starting from scratch we would use RTD types - more accurate and reliable. BTW, those controllers are in the $90 to $130 range normally.

dreamboat said:
I am a *******, and I know it for having to mention this you all....
You JAMMY *******


$13 thermocouple probe from Jaycar was suitable for all three units, and confirms that they are all working. Now I need to make a decision as to whether to use thermocouples or the Pt100 type ....
And I need to decide what use I may have for three more temp controllers above the one which I already have.
One dedicated for the fridge
One for the HLT
Maybe one for the mash recirculation pump....

Can't have too many I'm sure

dreamboat said:
One dedicated for the fridge
One for the HLT
Maybe one for the mash recirculation pump....
I have three and thats exactly what i do, fridge,HLT and mash tun recirc pump.
Mine are all k100 thermocouples' and are not the very best to use but still do work well. I don't know that much about them exept i have heard they are designed for maintaining temps much higher than brewers temp, ie more like 800c than 80c, but they do work quite well for the temps we need.
Mine have just started to be a little dodgey and will be replaced with RTDs' and like everyone else here i would say try to find RTDs' if you can.
My units can take pretty much any type of probe out there.

Here's a pic!


I have just spoken with a man in the temp control game (who we buy a bit of gear off - so he looks after me), and he said that the NTC type of probe, which is of the Pt100 type, he can buy thm for around $15 each from his supplier... so not much dearer than the thermocouple type.
He is going to track one down for me to try in my units, then I will likely buy them to use permanently.

If you just buy some thermocouple comp cable, of the correct type for your controller, eg K type, you can make a thermocouple simply by stripping the cable back and twisting the pair together. That way you cam make as many sensors as you like.
This is what I do, and I stick one on each of my fermenters so as the temperature control them during ferment.
I like the sound of this vlbaby... would make it ver easy to leave thermocouplpes wherever you want them, and just plug the one into the controller which is of interest.
Is this sort of cable available from jaycar, dick smith and the like? Or will it be a bit tougher to track down?


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